Sound producer and receiver



Filed March 10, 1945 E. E. TURNER, JR

SOUND PRODUCER AND RECEIVER 3 Sheets-Sheet l IFH' INVENTOR.

EDWIN E.TURNER JR.

HIS ATTORNEY E. E. TURNER, JR

SOUND PRODUCER AND RECEIVER 3 Sheets-Sheet 2 Filed March 10, 1945 44 INVENTOR.

EDWIN E. TURNER JR.

add/M HIS ATTORNEY PEG. 3

{ A #1 Get 26, 1948. E RNER, JR

SOUND PRODUCER AND RECEIVER 3 Sheets-Sheet 3 Filed March 10, 1945 v ZNVENTOR.

EDWIN E. TURNER JR HIS ATTO NEY Patented Oct. 26, 1948 SOUND PRODUCER AND RECEIVER Edwin E. Turner, Jr., West Roxbury, Mass.,' as-' slgnor, by mesne assignments, to Submarine Signal Company, Boston, Mass, a corporation of Delaware Application March 10, 1945;Serial No. 582,110

5 Claims. (Cl.177386) granted October 29, 1946. The earliest of the three cases above mentioned relates to a concentric ring oscillator in which the rings operate directly against a plate by means of electrody- 'namic methods applied at the ends of the rings.

In my application No. 78,719 a concentric system of horns of revolution are shown which are driven by short elements operating electrodynamically. In application No. 168,920 a concentric ring system is shown in which the concentric rings acting directly on a plate are of magnetostrictive material and are energized in the region adjacent to the plate.

'In the present system one of the features of the arrangement of the elements is that the ma netostrictive driving rings and the radiating plate are so constructed that a substantial ring area in the plate on either side of themagnetostrictive ring elements will radiate with a-.substantially uniform amplitude over the entire ring area. These radiating ring areas are formed with sections of a cycloidal arch in which the driving ring elements act at the base of the arch in directions normal to the radiating surface. I have found that a number of substantial advantages are gained in this design. A remarkably stiff arch is obtained with a comparative minimum of mass away from the driving point. In addition to this the vibratcry node in the system for the same general amplitude transformation is not as near the radiating plate as in other designs with the result that the driving coil can be efilciently located without crowding it near the plate where induced currents cause high eddy current losses.

In the present invention the driving element comprises concentric rings, each of which is formed of a number of laminations and which is welded, brazed, or rigidly attached to the base rings of the cycloidal arch in any well-known manner. The construction according to the present' invention will provide a large radiating surface substantially 4' in diameter or more and permit operation at frequencies in the range of 10,000 cycles without approaching a point at i which a plate resonance has any appreciable eflect.

The merits and advantages of the present invention will be more readily understood from the further description of the invention contained in the specification when taken in connection with the drawings illustrating an improvement of the same in which Figs. 1, 2 and 3 together show a completed central section through the device; Figs. 1 and 3 being the end portions and Fig. 2 the middle portion. Fig. 4 shows in reduced size a section taken parallel to the radiating surface of the oscillator. Fig. 5 shows a detail of the laminated magnetostrictive driving element.

In the drawings the compressional wave oscillator comprises a casing I which may be, and preferably is, cylindrical in shape recessed and covered with a rear cover 2. The front of the casing may be opened and adapted to receive the radiating cover or diaphragm 3 of the special form and shape which will be presently described. The casing itself may be supported by a neck 4 integral with a coupling flange 5 for attachment to a, shaft or other means for supporting the oscillator, in the medium in any suitable way desired. When the apparatus is used in water, as in submarine signaling, it may be attached to a shaft to be lowered down through the bottom of a ship or the device may project from a support on the vessel or it may be mounted in such a way as to be anchored at the sea bottom or suspended from a buoy or other means.

The invention more particularly concerns the' construction of the oscillator itself. The diaphragm or radiating surface 3 is provided with a clamping flange or ring 6 which is clamped tightly by means of the bolt 1 to the casing i. A suitable water-tight gasket 8' may be imbedded in a groove in the clamping surface of the casing for engaging a tongue projecting from the clamping ring of the diaphragm. The diaphragm, or radiating plate, which is preferably of a hard metallic element such as steel is permeable to magnetic flux so as to complete a magnetic circuit to the driving elements which will be explained later. The outer surface of the radiating plate is preferably flat and uniform while the inner surface of the plate is symmetrical with a central axis normal to the plate with radial normal sectionsformed in repeated cycloidal arches as indicated by the arches 8, 9, and H! of Fig. 1. The cycloidal arches, when looking in a direction normal to the diaphragm, are annular in shape and come together in V-like bases II, I2 and I 3 at which point the concentric magnetostrictive cylinders I4, I5 and I6 are attached. These cylinders are laminated as indicated in Fig. 5 and comprise preferably 3 laminated elements I1, I8 and I9 which have preferably oxidized surfaces and which are snugly nested, one to the other, so that there will be no relative motion between any adjacent elements.

The magnetostrictive rings I4, I5 and I6 are Welded into the bases of the cycloidal arches or firmly attached in some other manner. Each magneto-restrictive ring drives a section of the radiating face; these sections being the annular surfaces bounded by the thinnest sections of the arc. The material within such sections provides the greatest strength for the least weight and permits a comparatively large radiating annulus with a single driving element.

As has been explained in my early co-pending application No. 677,179, filed June 23, 1933, now

Patent No. 2,407,328, granted September 10, 1946,

a transformation of linear amplitude takes place between the radiating face and the magnetostrictive ring. In the application 677,179 the design of the structure was such that the node of the vibrating rods was positioned near the plate or radiating element. In the present design the stiffness of the annular sectors are such that the mass of the radiating structure is lighter than if it were a plate of uniform thickness; the

result of this is that the node in the magnetostrictive vibrating cylinder is not crowded towards the radiating plate but on the other hand may be a slight distance away somewhere adjacent to the position of the concentric driving coils 20, 2| and 22. The positioning of the node in the magnetostrictive cylinders in this manner will have the efiect of decreasing the ratio of amplitude transformation and as a result the annular radiatin area may be provided with a greater amplitude.

A further advantage is gained in this arrangement in that the exciting coils 20, 2I and 22 do not induce leakage flux into the diaphragm which is of magnetic material.

The coils 20, 2| and 22 are cylindrical in form. A section of the central coil 23 is shown in Fig. 2 and the next outer coil 24 also in this figure. Each coil is mounted on an insulating form or core, the central one of which, 25, may be solid and recessed around the side walls to receive the coil 23. The top surface of the core 25 which may be of wood, Bakelite, or other similar insulating material is shaped in the same form as the cycloidal arch adjacent to it. The arch and the surface of the core are spaced apart suiiiciently so that at the maximum operating amplitude of the diaphgram the arch will just clear the surface of the core. The base of the core may be supported on an insulating plate 25 of similar material as the core 25 and this base in turn is mounted and supported on the rear cover 2 of the case. A system of suitable air vents and grooves may be provided through the cores and the plates as will be presently explained. The core or form member 21 adjacent to the core member 25 is cylindrical in shape with a hollow central section in which the core 25 is positioned. The outer upper surface of the form 21 is shaped in section to conform to the shape of the cycloidal arch and has a similar clearance as the core 25 to permit free vibration of the radiating member. All of the other cores 28, 29, 30 and SI are similarly constructed as the core 21. Together all these forms of cores provide a protection for the diaphragm or radiating member against a sudden depth charge which may press the diaphragm against the cores but prevent further strain so as to prevent a break or crack in the diaphragm either in the thin annuual webs between the cycloidal sections or in the thin peripheral joining web 32 which joins the clamping ring with the outer periphery of the radiatin member. The coils previously mentioned may carry both the oscillatory electric current and a direct polarizing current if desired. However, initial polarization may be obtained by use of permanent magnetizing elements which are in the shape of flat annular members concentrically positioned within the magnetostrictive cylinders I6,

I5, I4 and 33.

As indicated in the drawings, the rings 34, 35,

36 and 3'I' are mounted between the non-magnetic base element 26 and the coil supporting forms. The rings are magnetized with one polarity on the inside and the other polarity on the outside and are so supported in the same plane that one pole on the circumference of the ring is adjacent to the opposite pole on the circumference of the next ring. By this means the free end of the magnetostrictive rings I4, I5, 16 and 33 dip into a a permanent magnetic field which crosses the end sections of the magnetostrictive cylinders. The non-magnetic plate 26 is gouged out to provide recesses for the magnetostrictive rings.

The magnetic circuit in this arrangement is completed through the magnetizing rings, the magnetostrictive ring, the cycloidal arch section of the diaphragm and the nearest adjacent magnetostrictive ring. The fact that the adjacent poles of the permanent magnets are opposed to one another forces the flux into the magnetostrictive rings and sets up a magnetomotive force for completing the magnetic circuit through the magnetostrictive rings and the radiating plating.

The coils 23, 24, 20, 2| and 22 are excited by oscillatory current and the variation in magnetic flux inducd thereby in the magnetostrictive rings produces longitudinal vibration of the rings for vibrating the arched sections of the diaphragm. A large amplitude of the magnetostrictive cylinders, at their free ends, is converted into a smaller but uniform amplitude on the face of the annular sections of the diaphragm. If desired each annular ring may be designed to have difererit amplitudes for producing the desired diaphragm characteristics such, for instance, as reducing the auxiliary lobe and increasing the maximum lobe as disclosed in my copending application Serial No. 466,073, filed November 18, 1942.

In the operation of the system the inside of the casing may be hermetically sealed and under gas pressure. In order to relieve the gas pressure between the coil forms and the diaphragm, vent passages 38, 39, 40 and 4| are provided for each air section above the coil forms; these connect with the air space 42 beneath the base support 26. This also connects with the space 43' about the inside of the casing. Suitable vents with seals 44 are provided through the back cover of the casing for exhausting the gas within the casing, and pumping in desired air or gases to the pressure most favorable for operating the device under the desired conditions. A pump valve and seal 45 in the bottom of the casing is also provided for this purpose.

Electrical connections are made to the oscillator through the neck portion 4 in which the cable 46 is hermetically sealed in any well-known manner. Different electrical cable connections are brought through the sealed stufling head 41 to the interior of the casing as shown in .sectlon in Fi 1.

As has been stated earlier in the specification,

one of the main purposes of the present inventionv is to provide a sound producing member adapted to operate in water for the production of an intense beam of compressional wave energy particularly in frequencies near or above the audible frequency range. In the present case the device disclosed is particularly useful for transmission at a frequency around 10,000 cycles with a large energy volume. To obtain the same eiiective beam pattern at this frequency it is necessary to enlarge the radiating area of the diaphragm or radiating member and the present invention is particularly adaptable to permit the use of a greatly enlarged radiating member for the production of a beam with characteristics in which auxiliary lobes are maintained at a minimum and the main lobe at a maximum output of energy.

It will be noted that the oscillator casing may be provided with a sound insulating cover comprising a rubber or synthetic rubber shell 50 over whicha thin metal cover may be placed. As indicated in Fig.3, this may be made in two parts and clamped together through adjacent clamping flanges 53 and 54.

Fig. 5 shows in enlargement a fragmentary view of the concentric ring in section. It will be noted that the ring I! may be made up of a number of laminations which are welded into the vertex 55 of the base between the arches 9 and i0.

Having now described my invention, I claim:

1. Means for producing a beam of compressional waves comprising a radiating member having a substantially plane surface on one side and the other side formed with concentric annular areas having radial sections in the form of cycloldal arches, and vibratory means comprising concentric cylindrical members firmly attached at the vertices formed by the cycloldal arches, an energizing coil positioned between the ends of the cylindrical members, said cylindrical members comprising magnetostrictive elements forming with the radiating member tuned vibratory systems with vibrational nodes in said cylindrical member away from the base of the cycloldal arches in the vicinity of said energizing coils.

2. Means for producing a beam of compressional waves comprising a radiating member having a substantially even surface on one side and having a symmetrical center axis, and on the other side symmetrical concentric areas having sections radial with the central axis formed as cycloldal arches and vibratory members operatively attached to the base of the cycloldal arches vibrating in a direction parallel to the center axis. at a desired frequency, said vibratory members forming with the radiating member tuned vibratory systems with vibrational nodes in said vibratory members away from the base of the cycloldal arches and energizing coils positioned between the ends of the vibratory members extending over the place of the vibratory node.

3. A means for producing a beam of compressional waves comprising a radiating member having a peripheral supporting ring element and a plurality of inner annular concentric sections having cross sections formed as cycloldal arches with thin joining regions and athin Joinin region joining the outer annulus to the supportin ring, a recessed casing having an edge sur face to which said supporting ring is clamped, a plurality of concentric cylindrical magnetostrictive elements with axes positioned normal to the radiating face and joined thereto at the bases of said cycloldal arches, a plurality of concentric flat annular members having permanent magnets positioned in the ring space between the magnetrostrictive cylindrical elements towards the free ends thereof and poled to provide similar polarities at the inner edge of one ring and the outer edge of the other and energizing coils, one positioned within each of said cylindrical elements between the base of the radiating arch and said permanent magnet members.

4. A means for producing a beam of compressional waves comprising a radiating member having a peripheral supporting ring element and a plurality of inner annular concentric sections having cross sections formed as cycloldal arches with thin joining regions and a thin joining region joining the outer annulus to the supporting ring, a recessed casing having an edge surface to which said supporting ring is clamped, a plurality of concentric cylindrical magnetostrictive elements with axes positioned normal to the radiating face and joined thereto at the bases of said cycloldal arches, a plurality of concentric flat annular members having permanent magnets positioned in the ring space between the magnetostrictive cylindrical elements towards the free ends thereof and poled to provide similar polarities at the inner edge of one ring and the outer edge of the other and energizing coils, one positioned within each of said cylindrical elements between the base of the radiating arch and said permanent magnet members, and coil forms on 1 which said coils are mounted, said forms having contours at the top similar to the inner face of the radiating member and means positioning said forms whereby the top surfaces thereof opposed to the inner face of the radiating member are spaced just sufliciently away from the same whereby the normal vibration of the radiating face is not disturbed.

5. A means for producing a beam of compressional waves comprising a radiating member having a substantially even surface on one face and a plurality of annular concentric sections formed on the other face as cycloldal arches with thin joining regions between said sections, a plurality of thin cylindrical members firmly attached at the bases of said cycloldal arches, said cylindrical members forming with the annular sections of the radiating member a vibratory system with a node positioned in the cylindrical elements spaced away from the radiating member, and means disposed at the node for energizing said cylindrical elements.

EDWIN E. TURNER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

